Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 18 de 18
Filtrar
1.
J Radiol ; 88(1 Pt 1): 86-92, 2007 Jan.
Artigo em Francês | MEDLINE | ID: mdl-17299376

RESUMO

Angioplasty of stenoses of the carotid bifurcation is a revascularization procedure that is used successfully in many patients. With more than 10 years of experience now, the feasibility of carotid stenting has been demonstrated. Its distribution is highly variable depending on the country, with a mean penetration rate in Europe of 15% of the number of carotid revascularizations. However, the complication rate is highly variable from one series to another and depends on the type of patient treated and the operator's learning curve. The results of the first two randomized studies comparing endarterectomy and carotid stenting, EVA 3S in France and SPACE in Germany, have just been published. The conclusions of these studies only relate to symptomatic patients, who make up a small proportion of revascularized patients. At 30 days, the French study concluded that surgery was better, and the German study showed no advantage to stenting. The analysis of these results compared to other publications should make it possible to best define the current indications for carotid stenting.


Assuntos
Estenose das Carótidas/cirurgia , Stents , Idoso , Feminino , França , Humanos , Masculino , Ensaios Clínicos Controlados Aleatórios como Assunto
2.
Stroke ; 35(1): e18-20, 2004 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-14657456

RESUMO

BACKGROUND AND PURPOSE: Whether cerebral protection during carotid angioplasty and stenting (CAS) is associated with a lower risk of periprocedural stroke or death remains to be established. We report on 80 patients randomized in the CAS arm of the Endarterectomy Versus Angioplasty in Patients With Symptomatic Severe Carotid Stenosis trial comparing CAS (with or without cerebral protection) with carotid surgery in patients with recently symptomatic, severe carotid stenosis. SUMMARY OF REPORT: The Safety Committee recommended stopping unprotected CAS, because the 30-day rate of stroke was 3.9 (0.9 to 16.7) times higher than that of CAS with cerebral protection (4/15 versus 5/58). CONCLUSIONS: Although this result was not based on a randomized comparison of unprotected versus protected CAS, it suggests that the use of cerebral protection devices during CAS reduces periprocedural strokes.


Assuntos
Angioplastia/efeitos adversos , Estenose das Carótidas/cirurgia , Filtração , Stents/efeitos adversos , Acidente Vascular Cerebral/etiologia , Acidente Vascular Cerebral/prevenção & controle , Angioplastia/instrumentação , Endarterectomia , Filtração/instrumentação , Filtração/métodos , Humanos , Complicações Intraoperatórias/etiologia , Complicações Intraoperatórias/prevenção & controle , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/prevenção & controle , Segurança
3.
J Radiol ; 84(1): 7-13, 2003 Jan.
Artigo em Francês | MEDLINE | ID: mdl-12637882

RESUMO

Follow-up color duplex sonography after arterial surgery or angioplasty for lower limb arterial disease evaluates the outcome of the procedure and searches for lesions compromising patency. The various types of lesions are described. After surgical bypass, lesions include stenosis, anastomotic abnormality (enlargement, false-aneurysm), arterio-venous fistula, intrinsic bypass abnormalities, and collections. After endoluminal treatment, the main lesions include residual stenosis, restenosis, and in-stent hyperplasia. Local complications related to arterial puncture are described. The frequency and the type of lesions encountered depend on the interval between the date of the revascularization and the follow-up examination.


Assuntos
Assistência ao Convalescente/métodos , Angioplastia/métodos , Arteriopatias Oclusivas/diagnóstico por imagem , Arteriopatias Oclusivas/cirurgia , Perna (Membro)/irrigação sanguínea , Ultrassonografia Doppler Dupla/métodos , Endarterectomia/métodos , Falha de Equipamento , Humanos , Recidiva , Stents/efeitos adversos , Fatores de Tempo , Resultado do Tratamento , Grau de Desobstrução Vascular
5.
Arch Mal Coeur Vaiss ; 93(4): 387-91, 2000 Apr.
Artigo em Francês | MEDLINE | ID: mdl-10816810

RESUMO

Percutaneous endovascular thromboaspiration is a valuable tool as illustrated by the case of a patient suffering from a large intracardiac tumour. Histological and immuno-histochemical analysis of the tumour fragments provided the diagnosis of a cardiac angiosarcoma. The patient was a 44 year old man admitted for a large sero-sanguinous pericardial effusion which recurred after drainage. The case was complicated by a haemorrhagic cerebrovascular accident unrelated to a secondary deposit. Initially suspected after transthoracic echocardiography, the diagnosis of a tumour invading the right atrium was confirmed by transoesophageal echocardiography and cardiac CT scan. Surgery was declined and as the diagnosis of lymphoma could not be excluded, the patient underwent biopsy by an original method of percutaneous thromboaspiration. This minimally invasive, low cost technique would appear to be a valuable alternative to other endovascular biopsy techniques (saber, biotome) and to surgical biopsy, and could be proposed as the technique of first intent in an a priori non-operable intra-cardiac tumour or when lymphoma is suspected.


Assuntos
Neoplasias Cardíacas/diagnóstico , Linfoma/diagnóstico , Adulto , Biópsia/métodos , Neoplasias Cardíacas/patologia , Humanos , Linfoma/patologia , Masculino , Procedimentos Cirúrgicos Minimamente Invasivos , Miocárdio/patologia , Derrame Pericárdico/etiologia , Sucção
6.
Ann Vasc Surg ; 13(6): 618-21, 1999 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-10541617

RESUMO

Hand ischemic steal syndrome due to a forearm arteriovenous fistula is a rare occurrence. We report here a case in which we applied a new diagnostic method to assess the efficacy of distal radial ligation to treat this syndrome. A favorable comparison of distal radial artery pressure measurements before and after temporary occlusion of the artery with a balloon catheter indicated that perfusion of the hand would be dramatically improved after surgical artery ligation.


Assuntos
Derivação Arteriovenosa Cirúrgica/efeitos adversos , Mãos/irrigação sanguínea , Isquemia/cirurgia , Artéria Radial/cirurgia , Diálise Renal , Angiografia , Pressão Sanguínea , Humanos , Isquemia/diagnóstico por imagem , Isquemia/etiologia , Isquemia/fisiopatologia , Ligadura , Masculino , Pessoa de Meia-Idade , Artéria Radial/fisiopatologia , Síndrome
7.
Rev Med Interne ; 20(4): 323-8, 1999 Apr.
Artigo em Francês | MEDLINE | ID: mdl-10327475

RESUMO

PURPOSE: This retrospective study was aimed at assessing immediate and mid-term results of percutaneous transluminal angioplasty for intermittent claudication in patients over 70 years of age, and the overall morbidity and mortality during follow-up. METHODS: Fifty-one percutaneous transluminal angioplasties were performed between 1993 and 1997 in 30 men and eight women (mean age: 78 +/- 5.2; range 71-91) for intermittent claudication (walking distance < 250 m). RESULTS: Angioplasties were supra-inguinal in 24 cases (47%) and infra-inguinal in 27 cases (53%). Clinical success (walking distance > 500 m) was obtained in 92% of the patients. Significant complications (5.9%) were inguinal hematoma requiring subsequent surgery in one patient and common femoral false aneurysms in two patients. Mean duration of hospitalization was 3 days and a half. After a mean follow-up of 25 months (range: 4-51 months), improvement in the walking distance was still present in 31 patients (82%). The condition of seven (18%) patients did not improve. No patient presented with critical ischemia. As well, no patient underwent surgical revascularization or amputation. However, the condition of eight (21%) patients required subsequent percutaneous transluminal angioplasty. Four (10.5%) patients died. Following percutaneous transluminal angioplasty, six (18%) patients presented with a major non-fatal clinical event. All the patients lived at home. CONCLUSION: Percutaneous transluminal angioplasty has little immediate risk when lesions are accessible and leads to positive mid-term clinical results in the treatment of intermittent claudication in patients over 70 years of age.


Assuntos
Angioplastia com Balão , Claudicação Intermitente/terapia , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Humanos , Masculino , Estudos Retrospectivos , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento
8.
J Thorac Cardiovasc Surg ; 112(4): 1046-53, 1996 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8873732

RESUMO

Retroperfusion of the coronary sinus does not provide homogeneous distribution of cardioplegic solution. The goal of this study was to analyze the distribution of flow during retrograde cardioplegic infusion in cadaveric human hearts with two different techniques of coronary sinus cannulation: (1) internal occlusion of the coronary sinus by balloon inflation and (2) external occlusion by tightening the orifice of the coronary sinus around a simple catheter. To evaluate differences between the two techniques, angiographic and electron-beam computed tomographic studies were performed. Computed digital angiography was performed on 14 hearts. Angiographic patterns varied according to type of coronary sinus cannulation. With the balloon inflation technique, the marginal vein and the anterior descending vein were perfused first; the posterior descending vein was not perfused. This vein was opacified secondarily through a venovenous anastomosis located at the apex of the heart. Backward flow into the right atrium (steal phenomenon) was demonstrated. At completion of retroperfusion, the inferior part of the septum remained poorly opacified. Conversely, angiographic findings after external occlusion of the coronary sinus revealed simultaneous injection of all venous channels. The entire septum was well opacified at completion of retroperfusion. Electron-beam computed tomographic study was performed on eight hearts with the external occlusion technique and nine with the internal occlusion technique. The computed tomographic findings confirmed the results of digital angiography. The peak myocardial enhancement and the peak rising rate of myocardial enhancement within the interventricular septum were significantly more important (p < 0.0001) when the external coronary sinus occlusion mode was used than when the internal coronary sinus occlusion mode was used. In all hearts except one, the right ventricular wall was not opacified, regardless of the type of cannulation and the type of radiologic analysis. This study demonstrates the importance of coronary sinus cannulation technique in optimizing the protection of the interventricular septum with retrograde cardioplegic infusion.


Assuntos
Soluções Cardioplégicas/administração & dosagem , Angiografia Coronária , Parada Cardíaca Induzida/métodos , Tomografia Computadorizada por Raios X , Adulto , Cateterismo/métodos , Vasos Coronários , Humanos , Técnicas In Vitro , Pessoa de Meia-Idade
10.
J Vasc Surg ; 24(2): 279-83, 1996 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8752041

RESUMO

We report on a novel approach to correcting iliac artery occlusions caused by aortic counterpulsation. Two patients who had leg ischemia after retrieval of an intraaortic balloon pump underwent angiograms that showed occlusion of the right external iliac artery because of dissection (one case) or thrombosis (one case). Percutaneous self-expandable stents were implanted in the occluded vessels, and they fully restored normal iliac patency with no complications and satisfactory midterm follow-up results. We conclude that iliac artery occlusion induced by aortic counterpulsation can be safely treated by implanting self-expandable stents in cases of acute iatrogenic dissection.


Assuntos
Artéria Ilíaca/lesões , Balão Intra-Aórtico/efeitos adversos , Doença Aguda , Dissecção Aórtica/diagnóstico por imagem , Dissecção Aórtica/etiologia , Dissecção Aórtica/cirurgia , Humanos , Artéria Ilíaca/diagnóstico por imagem , Artéria Ilíaca/cirurgia , Masculino , Pessoa de Meia-Idade , Punções , Radiografia Intervencionista , Stents , Trombose/diagnóstico por imagem , Trombose/cirurgia , Ferimentos e Lesões/diagnóstico por imagem , Ferimentos e Lesões/etiologia , Ferimentos e Lesões/cirurgia
11.
AJR Am J Roentgenol ; 166(5): 1173-9, 1996 May.
Artigo em Inglês | MEDLINE | ID: mdl-8615265

RESUMO

OBJECTIVE: The purpose of our study was to report long-term (more than 2 years of follow-up) angiographic patency after self-expandable stent implantation in the iliac artery and to identify patient- or procedure-related prognostic factors of angiographic patency. SUBJECTS AND METHODS: Ninety-five consecutive patients (101 arteries) underwent Wallstent implantation to treat claudication (n=95 limbs), rest pain (n=2), and nonhealing ulcer (n=3). Another patient was asymptomatic but was treated for acute occlusion of the iliac artery after coronary angioplasty. After implantation of self-expandable stents, we followed up by examining clinical and angiographic records at 6 months, 1 year, and annually thereafter. The Kaplan-Meier survival curve was used to determine primary and secondary patency rates. Primary patency was that achieved after the initial procedure only. Secondary patency was defined as that achieved after one or more successful additional percutaneous procedures within the stent or beyond the stent. Multivariate analysis using the Cox proportional hazard model was performed to identify predictive factors of angiographic failure, defined as restenosis of 50% or greater or occlusion. RESULTS: Four-year patency rates of 61% (primary) and 86% (secondary) were found (mean follow-up, 29 months). The following five factors were associated with long-term angiographic failure: occlusion of the superficial femoral artery (relative hazard = 5.21), absence of hypertension (relative hazard = 4.85), a stent diameter of less than 8 mm (relative hazard = 4.45), two or more stents implanted (relative hazard = 3.56), and current tobacco consumption (relative hazard = 2.46). CONCLUSION: Improved patency rates may be obtained by selecting patients for Wallstent implantation in the iliac artery based on five factors shown to be prognostically important.


Assuntos
Arteriopatias Oclusivas/terapia , Artéria Ilíaca , Stents , Adulto , Angioplastia com Balão , Arteriopatias Oclusivas/diagnóstico por imagem , Feminino , Seguimentos , Humanos , Artéria Ilíaca/diagnóstico por imagem , Tábuas de Vida , Masculino , Pessoa de Meia-Idade , Prognóstico , Modelos de Riscos Proporcionais , Radiografia , Stents/estatística & dados numéricos , Fatores de Tempo , Resultado do Tratamento , Grau de Desobstrução Vascular
12.
J Radiol ; 76(11): 1021-4, 1995 Nov.
Artigo em Francês | MEDLINE | ID: mdl-8594180

RESUMO

Two cases of isolated calcified lesions of the aorta are reported. The first observation is that of a 25 years old man suffering from mild intermittent claudication predominant in the left leg. Radiological examination showed a calcified isolated lesion of the infra renal abdominal aorta. The patient underwent surgical treatment (thromboendarteriectomy) and was asymptomatic after 6 months. The second observation concerns a 30 years old man treated for benign thrombocytemia in whom a severe arterial hypertension associated with a thoracic bruit was discovered incidentally. Radiological workup demonstrated a solitary calcified lesion of the descending thoracic aorta. Endarteriectomy was performed and the patient was still asymtomatic at 12 months. A review of the literature as well as physiopathological hypothesis and diagnostic and therapeutic management of these uncommon lesions is proposed.


Assuntos
Aorta Abdominal/patologia , Estenose da Valva Aórtica/patologia , Calcinose/diagnóstico , Claudicação Intermitente/etiologia , Adulto , Angiografia Digital , Aorta Abdominal/diagnóstico por imagem , Aorta Abdominal/cirurgia , Estenose da Valva Aórtica/diagnóstico por imagem , Estenose da Valva Aórtica/cirurgia , Constrição Patológica , Endarterectomia , Humanos , Masculino
14.
Radiology ; 193(1): 227-32, 1994 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8090896

RESUMO

PURPOSE: To evaluate percutaneous transluminal renal angioplasty (PTRA) in the treatment of renal branch artery stenoses caused by fibromuscular dysplasia. MATERIALS AND METHODS: The authors retrospectively studied the files of 20 consecutive hypertensive patients with 25 branch artery stenoses associated with 10 main renal artery lesions. Results at clinical and angiographic follow-up were assessed by means of life-table analysis. RESULTS: PTRA was technically successful in 21 of the 25 renal branch artery stenoses (84%). One of the technical failures was treated by means of selective embolization. Nine of the 10 associated main renal artery lesions were successfully dilated, and the 10th was improved. Immediately after PTRA, at 6-month follow-up, and at long-term follow-up, 70%, 76%, and 68% of the patients, respectively, were cured and 25%, 24%, and 16% were improved. Stenosis recurred in 9% of the branch arteries and was associated with clinical relapse; these arteries were redilated, and all patients were considered cured at the second 6-month follow-up. CONCLUSION: PTRA should be considered the first-line treatment for hypertension due to renal branch artery stenosis in fibromuscular disease.


Assuntos
Angioplastia com Balão , Displasia Fibromuscular/terapia , Hipertensão Renovascular/prevenção & controle , Obstrução da Artéria Renal/terapia , Adolescente , Adulto , Feminino , Displasia Fibromuscular/diagnóstico por imagem , Displasia Fibromuscular/epidemiologia , Seguimentos , Humanos , Hipertensão Renovascular/epidemiologia , Tábuas de Vida , Masculino , Radiografia , Recidiva , Obstrução da Artéria Renal/diagnóstico por imagem , Obstrução da Artéria Renal/epidemiologia , Estudos Retrospectivos , Fatores de Tempo , Resultado do Tratamento
15.
Cardiovasc Surg ; 2(4): 460-2, 1994 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-7953448

RESUMO

A 34-year-old woman, who had undergone a thoracic aortic aneurysmectomy and replacement with a prosthetic tube graft several months previously, presented with a pseudoaneurysm arising from the proximal anastomotic site. This pseudoaneurysm was studied with contrast-enhanced ultrasfast computed tomography. The exact location of the suture dehiscence was located by the presence of a contrast jet flow through the aortic wall. This case shows the feasibility of demonstrating blood flow at the entry site of a pseudoaneurysm with ultrafast computed tomography which may avoid conventional angiography.


Assuntos
Aneurisma da Aorta Torácica/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Adulto , Prótese Vascular , Feminino , Humanos , Complicações Pós-Operatórias/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos
16.
Arch Mal Coeur Vaiss ; 86(12): 1683-9, 1993 Dec.
Artigo em Francês | MEDLINE | ID: mdl-8024369

RESUMO

Twenty years after its first introduction by A. Carpentier, the use of the radial artery (RA) for coronary bypass was reinvestigated because of unexpected good long term results in some patients. Since July 1989, 158 patients (pts) underwent myocardial revascularization using 189 RA grafts (31 pts received 2 grafts). The left internal mammary artery (LIMA) was concomitantly used as a pedicled graft in 151 cases and the right internal mammary artery (RIMA) in 31 cases, a free IMA graft was used in 29 cases and a saphenous vein graft in 40 cases. A mean of 2.8 graft/pt was performed. The target artery receiving the RA was: circumflex (n = 93), diagonal (n = 39), right coronary (n = 47) and LAD (n = 10). Two patients died (1.3%) and three presented a perioperative myocardial infarct (2.5%). Sternal wound infection was noted in three cases of double IMA implant. No ischemia of the hand was observed. All patients received diltiazem started intraoperatively and continued after discharge. In addition, aspirin (100 mg/day) was given at discharge. Early angiographic controls (< 3 weeks) were obtained in the first 60 consecutive patients and revealed: 73/73 patent RA grafts, 58/58 patent LIMA grafts, 16/16 patent RIMA grafts, 15/19 patent free IMA grafts and 10/11 patent vein grafts. Six patients presented a localized narrowing of the RA conduit unrelated to the anastomotic lines (spasm). Late angiographic control (6 to 24 months) was obtained after a mean follow-up of 11 months in 37 patients: 42/46 RA grafts were patent (91.3%) and free of spasm and 4 were occluded.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Ponte de Artéria Coronária/métodos , Doença das Coronárias/cirurgia , Artéria Radial/transplante , Adulto , Idoso , Angiografia Coronária , Feminino , Seguimentos , Oclusão de Enxerto Vascular , Humanos , Anastomose de Artéria Torácica Interna-Coronária , Masculino , Pessoa de Meia-Idade , Espasmo/diagnóstico por imagem
17.
Arch Mal Coeur Vaiss ; 86(10): 1445-50, 1993 Oct.
Artigo em Francês | MEDLINE | ID: mdl-8010842

RESUMO

The aim of this study was to evaluate the early postoperative angiographic features of arterial coronary bypass grafts in 83 asymptomatic patients referred consecutively from the surgical unit. The patients aged 33 to 78 years (average 62 years) were operated between August 1989 and March 1992 and received only arterial coronary bypass grafts: 209 arteries bypassed (121 internal mammary including 10 sequential grafts, 46 radial, 36 epigastric including 4 sequential grafts and 6 gastroepiploic arterial grafts), an average of 2.4 bypass grafts per patient. Selective angiography of the arterial grafts was performed systematically between the 7th and 15th postoperative days in patients with uncomplicated recoveries. The native coronary arterial network was opacified only when a graft was "non-functional": haemodynamic (> 70%) stenosis or occlusion. 3.8% of pediculated mammary grafts were occluded. On the other hand, 16.6% of free internal mammary grafts were occluded. None of the radial artery grafts were occluded, but 8% were stenotic. Finally, 30% of epigastric and 50% of the gastroepiploic grafts were occluded. These results confirm the good function of in situ mammary artery grafts by suggest that systematic multiple arterial grafts should be used with caution. Radial artery grafts give very encouraging results which require long-term evaluation. Early postoperative evaluation of coronary arterial grafts provides important information and should be considered a routine procedure.


Assuntos
Artérias/transplante , Angiografia Coronária , Ponte de Artéria Coronária/métodos , Oclusão de Enxerto Vascular/diagnóstico por imagem , Anastomose de Artéria Torácica Interna-Coronária , Músculos Abdominais/irrigação sanguínea , Adulto , Idoso , Ponte de Artéria Coronária/efeitos adversos , Humanos , Anastomose de Artéria Torácica Interna-Coronária/efeitos adversos , Pessoa de Meia-Idade , Artéria Radial/cirurgia , Grau de Desobstrução Vascular
18.
Ann Thorac Surg ; 54(4): 652-9; discussion 659-60, 1992 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-1358040

RESUMO

Eighteen years after its first introduction for coronary artery revascularization, the radial artery (RA) was reinvestigated because of unexpected good long-term results in the early series. Since July 1989, 104 patients underwent myocardial revascularization using 122 RA grafts (18 patients received two grafts). The left internal mammary artery (IMA) was concomitantly used as a pedicled graft in 100 cases and the right IMA in 19 cases; a free IMA graft was used in 29 cases and a saphenous vein graft in 24 cases. A mean of 2.8 grafts per patient were performed. Nine patients underwent associated procedures: carotid endarterectomy (3), aortic valve replacement (3), Bigelow procedure (1), and mitral valve repair (2). The target artery receiving the RA was the circumflex (n = 59), diagonal (n = 29), right coronary (n = 27), and left anterior descending (n = 7). One patient died (0.96%) and 2 had perioperative myocardial infarct. Sternal wound infection was noted in 3 cases of double IMA implantation. No ischemia of the hand was observed. All patients received diltiazem started intraoperatively and continued after discharge. In addition aspirin (100 mg/day) was given at discharge. Early angiographic controls (less than 2 weeks) were obtained in the first 50 consecutive patients and revealed 56 of 56 patent RA grafts, 48 of 48 patent left IMA grafts, 11 of 11 patent right IMA grafts, 14 of 18 patent free IMA grafts, and 8 of 9 patent vein grafts.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Braço/irrigação sanguínea , Ponte de Artéria Coronária/métodos , Adulto , Idoso , Artérias/transplante , Angiografia Coronária , Diltiazem/uso terapêutico , Feminino , Seguimentos , Oclusão de Enxerto Vascular/diagnóstico por imagem , Oclusão de Enxerto Vascular/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Revascularização Miocárdica , Complicações Pós-Operatórias/diagnóstico por imagem , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/prevenção & controle , Veia Safena/transplante , Espasmo/diagnóstico por imagem , Espasmo/prevenção & controle , Resultado do Tratamento , Doenças Vasculares/diagnóstico por imagem , Doenças Vasculares/prevenção & controle , Grau de Desobstrução Vascular
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA